Integrin-associated protein (IAP or CD47) is a receptor for thrombospondin family members, a ligand for the transmembrane signaling protein SIRPα and a component of a supramolecular complex containing specific integrins, heterotrimeric G proteins and cholesterol. Peptides containing a VVM motif in the C-terminal domain of thrombospondins are agonists for CD47, initiating heterotrimeric Gi protein signaling that augments the functions of integrins of the β1, β2 and β3 families, thus modulating a range of cell activities including platelet activation, cell motility and adhesion, and leukocyte adhesion, migration and phagocytosis.